This study seeks to (1) identify neuroanatomical, neurophysiological, and neuropsychological variables that are individually affected by age and/or chronic alcohol exposure; (2) describe the interactive effects of age and alcohol use on individual measures; and (3) identify patterns of correlation between the measures likely to be due to common underlying CNS processes. The specific measures to be obtained include performance on neuropsychological tests of recent and remote memory, verbal learning and visuospatial abilities; event-related potential measures of sensory and cognitive processing; and computerized tomographic measures of cortical and subcortical structure. Subjects ranging in age from 35 to 70 years will be studied: A high alcohol exposure group will be recruited from a alcoholism rehabilition program and a low alcohol exposure group will be recruited from the community at large. A 3-year follow up of both groups is planned for the purpose of identifying longitudinal effects of age and alcohol abuse and assessing the prognostic value of the variables in terms of morbidity, mortality and recidivism. Age-corrected values on each measure, based on analysis of data from the low alcohol exposure subjects, will be used to evaluate the effects of chronic alcohol use in the high alcohol use group. Further analysis will determine whether there are additional interactions between age and alcohol use on any variable. Predicted correlations between the performance, ERP, neurochemical, sleep, and CT scan variables will be tested, and the prognostic value of these measures, separately or in combination, will be evaluated.